With ongoing developments in display technology, a backlight module using a number of light-emitting diodes (LEDs) as light emitting devices for irradiating a liquid crystal display (LCD) has become widely used in a variety of consumer electronic devices, such as cellular telephones, computers, digital cameras, personal digital assistants (PDAs), and the like. The LEDs in the backlight module are arranged in a matrix manner in a tabular region having substantially the same shape as a panel of the LCD. The backlight module, on a back side of the LCD, irradiates, with light from the LEDs, in a planar orientation to the LCD. In the backlight module, a brightness distribution of light has been made substantially uniform by a lens.